Respiratory sinus arrhythmia and diseases of aging: obesity, diabetes mellitus, and hypertension

Disinhibition, rather than moderate-to-severe traumatic brain injury, moderates the impact of anger provocation on subjective emotional experience

OBJECTIVE

Altered reactivity to emotional stimuli is common after traumatic brain injury (TBI), which is suggested to reflect difficulties with emotion regulation. While disinhibition is common after moderate-to-severe TBI, limited research has investigated the link between disinhibition and emotional reactivity in this clinical group. The aim of this research, therefore, was to investigate the relationship between disinhibition and TBI to anger provocation.

METHOD

Thirty-five individuals with moderate-to-severe TBI and thirty-one controls completed an anger induction task. Participants rated their experience of emotions and subjective arousal before and after the induction. Heart rate, respiration and skin conductance were also measured. Disinhibition was measured using the Frontal Systems Behavior Scale.

RESULTS

In the full sample, the mood induction led to increased skin conductance, respiration, and self-reported anger, tension, arousal and negative mood. There were no differences between those with TBI and controls. Disinhibition interacted with the impact of anger provocation on subjective, but not objective, outcomes such that those elevated in disinhibition reported increased feelings of anger and tension in response to the mood induction. Disinhibition did not interact with TBI across any subjective and objective emotional measures examined in response to mood induction.

CONCLUSIONS

While anger causes emotional changes for all individuals, these changes are particularly pronounced among those who are disinhibited, irrespective of whether an individual has sustained a TBI. This is an important consideration when examining emotional regulation post-TBI as the degree of disinhibition appears to alter subjective interpretations of emotional events, which could lead to emotion dysregulation.

Childhood Family Stress and Women's Health: Parasympathetic Activity as a Risk and Resiliency Factor

Childhood family stress (CFS) exacerbates risk for physical health problems across the lifespan. Health risks associated with CFS are particularly relevant for women who tend to endorse more CFS than men. Importantly, some evidence suggests that individuals may vary in their susceptibility to CFS. Parasympathetic activity, which helps to regulate automatic bodily activity (e.g., breathing, digestion), has been proposed to represent a marker of plasticity to environmental exposure. However, no research to date has tested whether parasympathetic activity may modulate the impact of early adversity on health. We examined whether parasympathetic activity would moderate the link between CFS and health complaints in a sample of 68 undergraduate women (Mean age = 19.44). Participants self-reported CFS and health complaints. Parasympathetic activity was indexed using high-frequency heart rate variability (HF-HRV) and was evaluated by measuring changes in HF-HRV in response to and following a laboratory-based stress induction. Multiple regression analyses indicated that CFS was significantly associated with more health complaints. Further, HF-HRV in response to stress and during recovery relative to baseline significantly moderated relationship between CFS and health complaints. Specifically, more CFS was significantly associated with more health complaints among women who showed mean or greater decreases in HF-HRV in response to stress. Additionally, lower levels of CFS were associated with fewer health complaints among women who showed mean or greater HF-HRV during recovery relative to baseline. Findings highlight the importance of parasympathetic activity in modulating stress-health links.

Using spectral continuity to extract breathing rate from heart rate and its applications in sleep physiology

Introduction: ECG Derived Respiration (EDR) are a set of methods used for extracting the breathing rate from the Electrocardiogram (ECG). Recent studies revealed a tight connection between breathing rate and more specifically the breathing patterns during sleep and several related pathologies. Yet, while breathing rate and more specifically the breathing pattern is recognised as a vital sign it is less employed than Electroencephalography (EEG) and heart rate in sleep and polysomnography studies. Methods: This study utilised open-access data from the ISRUC sleep database to test a novel spectral-based EDR technique (scEDR). In contrast to previous approaches, the novel method emphasizes spectral continuity and not only the power of the different spectral peaks. scEDR is then compared against a more widely used spectral EDR method that selects the frequency with the highest power as the respiratory frequency (Max Power EDR). Results: scEDR yielded improved performance against the more widely used Max Power EDR in terms of accuracy across all sleep stages and the whole sleep. This study further explores the breathing rate across sleep stages, providing evidence in support of a putative sleep stage "REM0" which was previously proposed based on analysis of the Heart Rate Variability (HRV) but not yet widely discussed. Most importantly, this study observes that the frequency distribution of the heart rate during REM0 is closer to REM than other NREM periods even though most of REM0 was previously classified as NREM sleep by sleep experts following either the original or revised sleep staging criteria. Discussion: Based on the results of the analysis, this study proposes scEDR as a potential low-cost and non-invasive method for extracting the breathing rate using the heart rate during sleep with further studies required to validate its accuracy in awake subjects. In this study, the autonomic balance across different sleep stages, including REM0, was examined using HRV as a metric. The results suggest that sympathetic activity decreases as sleep progresses to NREM3 until it reaches a level similar to the awake state in REM through a transition from REM0.

Autonomic brain functioning and age-related health concerns

The autonomic nervous system (ANS) regulates involuntary bodily functions such as blood pressure, heart rate, breathing, and digestion, in addition to controlling motivation and behavior. In older adults, the ANS is dysregulated, which changes the ability of the ANS to respond to physiological signals, regulate cardiovascular autonomic functionality, diminish gastric motility, and exacerbate sleep problems. For example, a decrease in heart rate variability, or the variation in the interval between heartbeats, is one of the most well-known alterations in the ANS associated with health issues, including cardiovascular diseases and cognitive decline. The inability to perform fundamental activities of daily living and compromising the physiological reactivity or motivational responses of older adults to moving toward or away from specific environmental stimuli are significant negative consequences of chronic and geriatric conditions that pose grave threats to autonomy, health, and well-being. The most updated research has investigated the associations between the action responsiveness of older adults and the maintenance of their physiological and physical health or the development of mental and physical health problems. Once autonomic dysfunction may significantly influence the development of different age-related diseases, including ischemic stroke, cardiovascular disease, and autoimmune diseases, this review aimed to assess the relationship between aging and autonomic functions. The review explored how motivational responses, physiological reactivity, cognitive processes, and lifelong developmental changes associated with aging impact the ANS and contribute to the emergence of health problems.

Divergent emotional and autonomic responses to Cyberball in patients with opioid use disorder on opioid agonist treatment

The perception of social exclusion among patients with opioid use disorder (OUD) could be affected by long-term opioid use. This study explores the emotional and cardiac autonomic responses to an experience of ostracism in a sample of participants with OUD on opioid agonist treatment (OAT). Twenty patients with OUD and twenty healthy controls (HC) performed a ball-tossing game (Cyberball) with two conditions: Inclusion and Ostracism. We measured self-reported ratings of perceived threat towards one's fundamental needs and respiratory sinus arrhythmia (RSA) immediately after the game and 10 min after Ostracism (Reflective stage). Following ostracism, participants with OUD self-reported blunted feelings of threat to the fundamental need to belong. RSA levels were significantly suppressed immediately after ostracism and during the Reflective stage in comparison with HC, indicating an autonomic alteration in response to threatening social situations. Finally, only among HC higher perceived threats towards fundamental needs predicted increases in RSA levels, suggesting an adaptive vagal regulation in response to a perceived threat. Conversely, among patients with OUD the subjective response to ostracism was not associated with the autonomic reaction. OAT may have a protective effect against negative feelings of ostracism. However patients with OUD on OAT present poor autonomic regulation in response to social threats, which could reflect their trait hypersensitivity to social rejection.

Selective transduction and photoinhibition of pre-Bötzinger complex neurons that project to the facial nucleus in rats affects nasofacial activity

The pre-Bötzinger complex (preBötC), a key primary generator of the inspiratory breathing rhythm, contains neurons that project directly to facial nucleus (7n) motoneurons to coordinate orofacial and nasofacial activity. To further understand the identity of 7n-projecting preBötC neurons, we used a combination of optogenetic viral transgenic approaches to demonstrate that selective photoinhibition of these neurons affects mystacial pad activity, with minimal effects on breathing. These effects are altered by the type of anesthetic employed and also between anesthetized and conscious states. The population of 7n-projecting preBötC neurons we transduced consisted of both excitatory and inhibitory neurons that also send collaterals to multiple brainstem nuclei involved with the regulation of autonomic activity. We show that modulation of subgroups of preBötC neurons, based on their axonal projections, is a useful strategy to improve our understanding of the mechanisms that coordinate and integrate breathing with different motor and physiological behaviors. This is of fundamental importance, given that abnormal respiratory modulation of autonomic activity and orofacial behaviors have been associated with the development and progression of diseases.

Development and Parasympathetic Regulation in Male and Female Adolescents with Autism Spectrum Disorder: A Two-Timepoint Longitudinal Study

Prolonged dysregulation of the autonomic nervous system (ANS) may increase propensity for physical or psychiatric illness. The current study examined differences in respiratory sinus arrhythmia (RSA) regulation in 215 adolescents with or without autism spectrum disorder (ASD) at Time 1 (T1; 10-13 years old) and 1 year later (Time 2; T2). Linear mixed effects models demonstrated lower RSA regulation in ASD, and a small interaction effect, showing blunted change in RSA from T1 to T2. Developmental differences in RSA regulation were particularly notable in females with ASD and those taking psychotropic medications. Results expand previous findings of reduced parasympathetic regulation in ASD by revealing a blunted developmental slope, indicating diagnostic differences may persist or worsen over time, particularly in females.

Parental Preconception Adversity and Offspring Health in African Americans: A Systematic Review of Intergenerational Studies

Background: This systematic review explores the empirical literature addressing the association between parental preconception adversity and offspring physical health in African-American families. Method: We conducted a literature search in PubMed, Web of Science, PsycINFO, CINAHL, and Scopus through June 2021. Articles were included if they: reported data about at least two generations of African-American participants from the same family; measured parental preconception adversity at the individual level; measured at least one offspring physical health outcome; and examined associations between parental adversity and child health. Results: We identified 701 unique articles; thirty-eight articles representing 30 independent studies met inclusion criteria. Twenty-five studies (83%) reported that parental preconception adversity was associated with child health; six studies (20%) reported that parental preconception adversity was not associated with at least one offspring outcome; several studies reported both. Only six studies (20%) reported an association specific to African Americans. Conclusion: Empirical evidence linking parental preconception adversity with offspring physical health in African Americans is limited and mixed. In the current literature, very few studies report evidence addressing intergenerational associations between parental preconception adversity and offspring physical health in the African-American population, specifically, and even fewer investigate forms of parental preconception adversity that have been shown to disproportionately affect African Americans (e.g., racism). To better understand root causes of racial health disparities, more rigorous systematic research is needed to address how intergenerational transmission of historical and ongoing race-based trauma may impact offspring health among African Americans.

Diagnostic and Physical Effects in Parasympathetic Response to Social Evaluation in Youth With and Without Autism Spectrum Disorder

Individuals with autism spectrum disorder (ASD) may demonstrate atypical autonomic (ANS) responses; however, research remains inconsistent. This study examined parasympathetic response during social evaluation in 241 youth (10-13 years) with ASD (n = 138) or typical development (TD; n = 103). Diagnosis, age, pubertal development, and body mass index (BMI) were hypothesized to be associated with ANS function. Linear mixed effects models demonstrated lower RSA in ASD relative to TD in a base model with no covariates. However, when accounting for differences in BMI, there was no evidence of atypical parasympathetic regulation in youth with ASD. As lower parasympathetic regulation may increase susceptibility for a number of conditions, it will be important to elucidate the link between BMI and the ANS, especially in ASD.

Negative mood induction effects on problem-solving task in women with eating disorders: a multi-method examination

BACKGROUND

The effects of negative affect on problem-solving and its psychophysiological correlates are poorly understood in eating disorder populations.

METHODS

This study examined respiratory sinus arrhythmia (RSA) and skin conductance responses of women with Binge Eating Disorder (BED: n = 56), Anorexia Nervosa (AN: n = 12), Bulimia Nervosa (BN: n = 32), and 24 healthy controls (HCs) at baseline, and then during: a negative mood induction task, an adapted Means Ends Problem-Solving (MEPS) task, and recovery. The MEPS task included four interpersonal scenarios: (1) binge-eating as a solution to stress, (2) job loss, (3) rejection by friends, and (4) by a significant other.

RESULTS

We found that individuals with eating disorders reported less positive mood than HCs and individuals with BN and BED reported more negative mood and greater urges to binge than HCs. After a negative mood induction, women with BED provided significantly less effective problem-solving strategies compared to HCs and women with BN for the binge-eating MEPS scenario. Relative to baseline and the negative mood induction, all participants exhibited significantly higher skin conductance measures throughout the MEPS scenarios and recovery. BED showed significantly lower respiratory sinus arrhythmia (RSA) levels than individuals with BN and HCs throughout the protocol.

CONCLUSIONS

The multimethod findings suggest individuals with BED are likely to have disorder-specific problem-solving difficulties after a negative mood induction.

Cardiovascular Responses to Commonly Used Tests in and Outside of the Laboratory Settings

Several tests are available for assessing cardiovascular response to various interventions which may be given in the laboratory, or outside of it in the field. The tests are meant to excite or deactivate cardiovascular and other sensory receptors which signal the central mechanisms. They have been found useful in generating data to study cardiovascular effects on subjects exposed to specialized physical training (e.g., athletes), in the evaluation of people engaged in special occupations such as pilots, astronauts, and other military personnel, and in training undergraduate and postgraduate students. If the response does not fit into the physiological norm, it may reflect a temporary aberration, or a more serious defect in the cardiovascular control mechanism because of disease. Interpretation of data generated may vary between various operators/observers. Here, an attempt has been made to bring out responses of the cardiovascular system to the commonly used tests, and their applicability in clinical situations.

The Importance of Biobehavioral Research to Examine the Physiological Effects of Racial and Ethnic Discrimination in the Latinx Population

A growing body of research is documenting how racial and ethnic populations embody social inequalities throughout the life course. Some scholars recommend the integration of biospecimens representing the hypothalamic-pituitary-adrenal axis, neurological and endocrinological processes, and inflammation to capture the embodiment of inequality. However, in comparison to other racial and ethnic groups, there has been little research examining how Hispanic/Latinx persons embody racial and ethnic discrimination, much less resulting from institutional and structural racism. We provide a rationale for expanding biobehavioral research examining the physiological consequences of racism among Latinx persons. We identify gaps and make recommendations for a future research agenda in which biobehavioral research can expand knowledge about chronic disease inequities among Latinx populations and inform behavioral and institutional interventions. We end by cautioning readers to approach the recommendations in this article as a call to expand the embodiment of racism research to include the diverse Latinx population as the United States addresses racial inequity.

Heart rate variability and HbA1c predict plasma interleukin-6 response to psychosocial stress challenge in trauma-exposed women with type 2 diabetes

Background

Type 2 diabetes mellitus (T2DM) is a major public health problem in the United States. Although cardiovascular autonomic functioning, blood glucose control, and inflammation are known to play a role in T2DM, the interaction between these variables remains largely unexplored, particularly in the context of stress. To address this gap, we examined the relationship between these variables in a sample that is uniquely vulnerable to the health consequences of T2DM.

Methods

Participants were 37 trauma-exposed Black women with a diagnosis of T2DM. High frequency heart rate variability (HF-HRV), blood glucose control (HbA1c), and a stressor-evoked biomarker of inflammation (interleukin 6; IL-6) were obtained as part of a larger study of the genetic risk factors for and consequences of trauma exposure.

Results

The interaction of HbA1c and HF-HRV was significantly associated with IL-6 response calculated as area under the curve with respect to ground. Post-hoc simple slopes analyses revealed HbA1c, rather than HF-HRV, as the moderator in this association such that higher HF-HRV conferred higher circulating levels of IL-6 only in the presence of lower HbA1c, (β ​= ​0.60, t ​= ​3.51, p ​= ​.001).

Conclusions

Cardiovascular autonomic functioning and blood glucose control were significantly associated with stressor-evoked IL-6 responses when controlling for BMI and age. Moreover, the association between cardiovascular autonomic functioning and inflammation varied at different levels of HbA1c. This highlights the possibility that individuals with trauma exposure and T2DM may benefit from stratification by HbA1c levels for research analysis and treatment decision making.

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The interaction of blood glucose and vagal control was associated with IL-6 response.

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Higher vagal control conferred more inflammation only when blood glucose was low.

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Stratification by HbA1c levels may be useful for research analysis.

Autonomic vulnerability to biased perception of social inclusion in borderline personality disorder

BACKGROUND

Individuals with Borderline Personality Disorder (BPD) feel rejected even when socially included. The pathophysiological mechanisms of this rejection bias are still unknown. Using the Cyberball paradigm, we investigated whether patients with BPD, display altered physiological responses to social inclusion and ostracism, as assessed by changes in Respiratory Sinus Arrhythmia (RSA).

METHODS

The sample comprised 30 patients with BPD, 30 with remitted Major Depressive Disorder (rMDD) and 30 Healthy Controls (HC). Self-report ratings of threats toward one's fundamental need to belong and RSA reactivity were measured immediately after each Cyberball condition.

RESULTS

Participants with BPD showed lower RSA at rest than HC. Only patients with BPD, reported higher threats to fundamental needs and exhibited a further decline in RSA after the Inclusion condition.

CONCLUSIONS

Individuals with BPD experience a biased appraisal of social inclusion both at the subjective and physiological level, showing higher feelings of ostracism and a breakdown of autonomic regulation to including social scenarios.

Emotion and Psychophysiological Responses During Emotion-Eliciting Film Clips in an Eating Disorders Sample

Background: Greater vulnerability to negative emotions appears associated with the development and maintenance of eating disorders (EDs). A systematic review of psychophysiological studies using emotion-eliciting film clips reveals that there are no studies examining the effect of standardized validated film clips on psychophysiological response across a range of EDs.

Methods: Using standardized validated film clips without ED-specific content, the present study examined self-reported emotions and psychophysiological responses of women with Binge-Eating Disorder (BED; n = 57), Anorexia Nervosa (AN; n = 16), Bulimia Nervosa (BN; n = 34), and Healthy Controls (HCs; n = 26) at Baseline, during Neutral, Sad, Happy, and Fear-inducing film clips, and at Recovery.

Results: Throughout the protocol, the ED groups reported significantly greater sadness and anxiety than HCs. Additionally, the AN group reported more fear, the BED group more frustration, and the BED and BN groups more tension than HCs. Compared to HCs, the BED group reported stronger urges to binge throughout the protocol, whereas BN group reported stronger urges to binge relative to the HC group only at Baseline and Recovery. The BN and BED groups experienced decreased urges to binge during all film clips compared to Baseline. Respiratory Sinus Arrhythmia levels were significantly lower in the BED group compared to HCs and the BN group throughout the protocol.

Discussion: Standardized validated film clips can be used to elicit expected self-reported emotion and skin conductance responses in ED groups, although individuals with EDs compared HCs report greater negative emotions. Interestingly, film clips appeared to reduce urges to binge in binge-eating groups.

Influences of adversity across the lifespan on respiratory sinus arrhythmia during pregnancy

There is limited understanding of factors across the lifespan that influence pregnant women's respiratory sinus arrhythmia (RSA), which could have implications for their health and offspring development. We examined associations among 162 English- and Spanish-speaking pregnant women's childhood maltreatment history, emotion dysregulation, recent life stress, and resting RSA during the third trimester. Moderated mediation analyses indicated that more severe childhood maltreatment history (95% confidence interval (CI) [0.26, 0.63]) and higher emotion dysregulation (95% CI [0.001, 0.006]) predicted more stress during pregnancy, and childhood maltreatment history interacted with emotion dysregulation to predict resting RSA (95% CI [-0.04, -0.0003]). Exploratory analyses revealed that women's health-related stress during pregnancy mediated the relation between emotion dysregulation and RSA regardless of childhood maltreatment severity (95% CI [-0.007, -0.002]). These findings suggest that women's resting RSA during pregnancy may reflect physical and emotional stress accumulation across the lifespan and that relations between early life adversity and prenatal psychophysiology may be buffered by protective factors, such as emotion regulation. In addition, these findings underscore the importance of distinguishing between types of prenatal stress. Given the implications for women's health and offspring development, we urge researchers to continue exploring factors associated with pregnant women's psychophysiology.

Conscientiousness and perceived physical symptoms: Mediating effect of life events stress and moderating role of resting respiratory sinus arrhythmia

This study investigated the possible psychophysiological links between conscientiousness and perceived physical symptoms by examining the mediating role of life events stress and the moderating role of resting respiratory sinus arrhythmia (RSA). Participants participated in the collection of questionnaire data and physiological data (N = 396). Results showed life events stress mediated the association between conscientiousness and perceived physical symptoms, and the indirect effect was only significant among individuals with lower resting RSA. Findings indicate that low resting RSA as a risk-amplifying physiological marker may magnify the relationship that low conscientiousness affects physical symptoms by increasing life events stress.

Respiratory variability of sinus node activation in humans: insights from ultra-high-density mapping

PURPOSE

Experimental data suggest that shifts in the site of origin of the sinus node (SN) correlate with changes in heart rate and P wave morphology. The direct visualization of the effect of respiration on SN electrical activation has not yet been reported in humans. We aimed to measure the respiratory shifting of the SN activation using ultra-high-density mapping.

METHODS

Sequential right atrial (RA) activation mapping during sinus rhythm (SR) was performed. Three maps were acquired for each patient: basal end-expiratory (Ex), end-inspiratory (Ins), and end-expiratory under isoproterenol (Iso). The earliest activation site (EAS) was defined as the earliest unipolar electrograms (EGM) with a QS pattern and was localized with respect to the ostium of the superior vena cava (SVC; negative values if EAS inside the SVC).

RESULTS

In 20 patients, 49 maps in SR were acquired (20 Ex, 19 Ins, and 10 Iso). Expiratory (944 ± 227 ms) and inspiratory (946 ± 227 ms) SR cycle lengths were similar, but shortened under isoproterenol (752 ± 302 ms). Activation was unicentric in 33 maps and multicentric in 16: 4 during Ins, 10 during Ex, and 2 Iso. EAS location was significantly more cranial in expiration than in inspiration (0.27 ± 12.1 vs 5 ± 11.51 mm, p = 0.01). Iso infusion tends to induce a supplemental cranial shift (-4.07 ± 15.83 vs 0.27 ± 12.7 mm, p = 0.21). EAS were found in SVC in 22.7% of maps (30% Ex, 21% Ins, and 8% Iso).

CONCLUSION

Inspiration induces a significant caudal shift of the earliest sinus activation. In one-third of the cases, sinus rhythm earliest activation is inside the SVC.

Resting Heartbeat Complexity Predicts All-Cause and Cardiorespiratory Mortality in Middle- to Older-Aged Adults From the UK Biobank

Background

Spontaneous heart rate fluctuations contain rich information related to health and illness in terms of physiological complexity, an accepted indicator of plasticity and adaptability. However, it is challenging to make inferences on complexity from shorter, more practical epochs of data. Distribution entropy (DistEn) is a recently introduced complexity measure that is designed specifically for shorter duration heartbeat recordings. We hypothesized that reduced DistEn predicted increased mortality in a large population cohort.

Method and Results

The prognostic value of DistEn was examined in 7631 middle‐older–aged UK Biobank participants who had 2‐minute resting ECGs conducted (mean age, 59.5 years; 60.4% women). During a median follow‐up period of 7.8 years, 451 (5.9%) participants died. In Cox proportional hazards models with adjustment for demographics, lifestyle factors, physical activity, cardiovascular risks, and comorbidities, for each 1‐SD decrease in DistEn, the risk increased by 36%, 56%, and 73% for all‐cause, cardiovascular, and respiratory disease–related mortality, respectively. These effect sizes were equivalent to the risk of death from being >5 years older, having been a former smoker, or having diabetes mellitus. Lower DistEn was most predictive of death in those <55 years with a prior myocardial infarction, representing an additional 56% risk for mortality compared with older participants without prior myocardial infarction. These observations remained after controlling for traditional mortality predictors, resting heart rate, and heart rate variability.

Conclusions

Resting heartbeat complexity from short, resting ECGs was independently associated with mortality in middle‐ to older‐aged adults. These risks appear most pronounced in middle‐aged participants with prior MI, and may uniquely contribute to mortality risk screening.

A method based on cardiopulmonary coupling analysis for sleep quality assessment with FPGA implementation

The relevance of sleep quality examination for clinical diagnosis is increasing with the discovery of new relationships with several diseases and the overall wellness. This assessment is commonly performed by conducting interviews with the subjects, evaluating the self-report and psychological variables. However, this approach has a major constraint since the subject is a poor self-observer of sleep behaviors. To address this issue, a method based on the examination of a physiological signal was developed. Specifically, the single-lead electrocardiogram signal was examined to estimate the cardiopulmonary coupling between the electrocardiogram derived respiration signal and the normal-to-normal sinus interbeat interval series. A one dimensional array was created from the coupling signal and was fed to a convolutional neural network to estimate the sleep quality. The age-related cyclic alternating pattern rate percentages in healthy subjects was considered as the classification reference. An accuracy of 91 % was attained by the developed model, with an area under the receiver operating characteristic curve of 97 %. The performance is in the upper range of the reported performance by the works presented in the state of the art, advocating the relevance of the proposed method. The model was implemented in a small field programmable gate array board. Hence, a home monitoring device was created, composed of a processing unit, a sensing module and a display unit. The device is resilient, easy to self-assemble and operate, and can conceivably be employed for clinical analysis.

Exploring the Effects of a Brief Biofeedback Breathing Session Delivered Through the BioBase App in Facilitating Employee Stress Recovery: Randomized Experimental Study

Background

Recovery from stress is a predictive factor for cardiovascular health, and heart rate variability (HRV) is suggested to be an index of how well people physiologically recover from stress. Biofeedback and mindfulness interventions that include guided breathing have been shown to be effective in increasing HRV and facilitating stress recovery.

Objective

This study aims to assess the effectiveness of a brief app-based breathing intervention (BioBase) in enhancing physiological recovery among employees who were induced to cognitive and emotional stress.

Methods

In total, we recruited 75 full-time employees. Interbeat (RR) intervals were recorded continuously for 5 min at baseline and during cognitive and emotional stress induction. The session ended with a 5-min recovery period during which participants were randomly allocated into 3 conditions: app-based breathing (BioBase), mindfulness body scan, or control. Subjective tension was assessed at the end of each period.

Results

Subjective tension significantly increased following stress induction. HRV significantly decreased following the stress period. In the recovery phase, the root mean square of successive RR interval differences (P=.002), the percentage of successive RR intervals that differed by >50 ms (P=.008), and high frequency (P=.01) were significantly higher in the BioBase breathing condition than in the mindfulness body scan and the control groups.

Conclusions

Biofeedback breathing interventions digitally delivered through a commercially available app can be effective in facilitating stress recovery among employees. These findings contribute to the mobile health literature on the beneficial effects of brief app-based breathing interventions on employees’ cardiovascular health.

Comparison of ECG-Derived Respiration Estimation Methods on Healthy Subjects in function of Recording Site and Subject Position and Gender

Respiration rate can be assessed by analyzing respiratory changes of the electrocardiogram (ECG). Several methods can be applied to derive the respiratory signal from the ECG (EDR signal). In this study, four EDR estimation methods based on QRS features were analyzed. A database with 44 healthy subjects (16 females) in supine and sitting positions was analyzed. Respiratory flow and ECG recordings on leads I, II, III and a Chest lead was studied. A QR slope-based method, an RS slope-based method, an QRS angle-based method and an QRS area-based method were applied. Their performance was evaluated by the correlation coefficient with the reference respiratory volume signal. Significantly higher correlation coefficients in the range r = 0.77 - 0.86 were obtained with the Chest lead for all methods. The EDR estimation method based on the QRS angle provided the highest similarity with the volume signal for all recording leads and subject positions. We found no statistically significant differences according to gender or subject position.Clinical Relevance- This work analyzes the EDR signal from four electrocardiographic leads to obtain the respiratory signal and contributes to a simplified analysis of respiratory activity.

Feasibility of Using a Single Heart Rate-Based Measure for Real-time Feedback in a Voluntary Deep Breathing App for Children: Data Collection and Algorithm Development

Background

Deep diaphragmatic breathing, also called belly breathing, is a popular behavioral intervention that helps children cope with anxiety, stress, and their experience of pain. Combining physiological monitoring with accessible mobile technology can motivate children to comply with this intervention through biofeedback and gaming. These innovative technologies have the potential to improve patient experience and compliance with strategies that reduce anxiety, change the experience of pain, and enhance self-regulation during distressing medical procedures.

Objective

The aim of this paper was to describe a simple biofeedback method for quantifying breathing compliance in a mobile smartphone app.

Methods

A smartphone app was developed that combined pulse oximetry with an animated protocol for paced deep breathing. We collected photoplethysmogram data during spontaneous and subsequently paced deep breathing in children. Two measures, synchronized respiratory sinus arrhythmia (RSA_sync) and the corresponding relative synchronized inspiration/expiration heart rate ratio (HR-I:E_sync), were extracted from the photoplethysmogram.

Results

Data collected from 80 children aged 5-17 years showed a positive RSA_sync effect in all participants during paced deep breathing, with a median (IQR; range) HR-I:E_sync ratio of 1.26 (1.16-1.35; 1.01-1.60) during paced deep breathing compared to 0.98 (0.96-1.02; 0.82-1.18) during spontaneous breathing (median difference 0.25, 95% CI 0.23-0.30; P<.001). The measured HR-I:E_sync values appeared to be independent of age.

Conclusions

An HR-I:E_sync level of 1.1 was identified as an age-independent threshold for programming the breathing pattern for optimal compliance in biofeedback.

Acute aerobic exercise increases respiratory sinus arrythmia reactivity and recovery to a sad film among individuals at risk for depression

Cardiac vagal control (CVC), as indexed by abnormalities in resting, reactivity, and recovery levels of respiratory sinus arrythmia (RSA), has been proposed as an index of impaired self-regulatory capacity in depression. Aerobic exercise has been shown to improve positive and negative affective responses and influence autonomic function; however, it is unknown whether exercise impacts RSA reactivity and subsequent recovery to emotional challenges among individuals at risk for depression. The present study aimed to determine the effects of moderate-intensity aerobic exercise on RSA reactivity and recovery to a sad film. Using a within-subjects design, 47 individuals with variable symptoms of depression completed a 30-min session of exercise and a sedentary control condition on separate days prior to viewing a sad film. On the control day, individuals with elevated depressive symptom severity displayed less vagal withdrawal to the sad film and exhibited impaired post-film RSA recovery. Following exercise, individuals with elevated depressive symptom severity demonstrated a higher degree of vagal withdrawal to the sad film and subsequent post-film recovery that matched individuals with lower depressive symptom severity. These findings suggest that a single session aerobic exercise may be an effective approach to increase emotional and self-regulatory capacity among individual at risk for, or currently experiencing, depression.

Multi-method assessment of palatable food exposure in women with and without eating disorders

OBJECTIVE

Eating disorders (EDs) are characterized by dysregulated responses to palatable food. Using a multi-method approach, this study examined responses to palatable food exposure and subsequent ad libitum eating in women with binge-eating disorder (BED: n = 64), anorexia nervosa (AN: n = 16), and bulimia nervosa (BN: n = 35) and 26 healthy controls (HCs).

METHOD

Participants were exposed to palatable food followed by an ad libitum eating opportunity. Affective and psychophysiological responses were measured before and during the task.

RESULTS

Participants with EDs reported greater negative affect, particularly fear, following the food cue exposure, whereas HCs reported no change. BN and BED groups reported greater urge to binge after the food cue exposure, whereas AN and HC groups reported no change. Respiratory sinus arrhythmia levels, skin conductance and tonic skin conductance levels increased during food exposure for all groups. Across baseline and during the food exposure, the BED group had lower respiratory sinus arrhythmia levels relative to the BN and HC groups. The BED group consumed significantly more palatable food than the AN group.

CONCLUSIONS

'Palatable' food stimuli elicited more negative affect, particularly fear, in individuals with EDs; and this, rather than psychophysiological responses, distinguishes individuals with EDs from those without.

Does Compassion Predict Blood Pressure and Hypertension? The Modifying Role of Familial Risk for Hypertension

Background

This study investigated (i) whether compassion is associated with blood pressure or hypertension in adulthood and (ii) whether familial risk for hypertension modifies these associations.

Method

The participants (N = 1112–1293) came from the prospective Young Finns Study. Parental hypertension was assessed in 1983–2007; participants’ blood pressure in 2001, 2007, and 2011; hypertension in 2007 and 2011 (participants were aged 30–49 years in 2007–2011); and compassion in 2001.

Results

High compassion predicted lower levels of diastolic and systolic blood pressure in adulthood. Additionally, high compassion was related to lower risk for hypertension in adulthood among individuals with no familial risk for hypertension (independently of age, sex, participants’ and their parents’ socioeconomic factors, and participants’ health behaviors). Compassion was not related to hypertension in adulthood among individuals with familial risk for hypertension.

Conclusion

High compassion predicts lower diastolic and systolic blood pressure in adulthood. Moreover, high compassion may protect against hypertension among individuals without familial risk for hypertension. As our sample consisted of comparatively young participants, our findings provide novel implications for especially early-onset hypertension.

Electronic supplementary material

The online version of this article (10.1007/s12529-020-09886-5) contains supplementary material, which is available to authorized users.

Anxiety, depressive symptoms, and cardiac autonomic function in perimenopausal and postmenopausal women with hot flashes: a brief report

OBJECTIVE

The aim of the study was to examine whether anxiety and depressive symptoms are associated with an adverse cardiac autonomic profile among midlife women with hot flashes.

METHODS

Anxiety and depressive symptoms were evaluated by validated self-administered questionnaires among peri- and postmenopausal women in a randomized trial of slow-paced respiration for hot flashes. Pre-ejection period (PEP), a marker of sympathetic activation, and respiratory sinus arrhythmia (RSA), a marker of parasympathetic activation, were measured at baseline and 12 weeks using impedance cardiography and electocardiography. Multivariable repeated measures linear regression models examined associations between anxiety and depression symptoms and autonomic markers, corrected for multiple comparisons with Benjamini-Hochberg procedure, and adjusted for age and body mass index.

RESULTS

Among the 121 participants, greater state anxiety was associated with shorter PEP, reflecting higher sympathetic activity (β = -0.24, P = 0.02). Greater trait anxiety and cognitive anxiety were associated with lower RSA, reflecting decreased parasympathetic activity (β = -0.03, P < 0.01 for Spielberger Trait Anxiety; β = -0.06, P = 0.02 for Hospital Anxiety and Depression Scale [HADS] Anxiety Subscale). Greater depressive symptoms were associated with lower RSA (β = -0.06, P = 0.03 for HADS Depression Subscale; β = -0.03, P = 0.04 for Beck Depression Inventory).

CONCLUSIONS

Among peri- and postmenopausal women with hot flashes, greater self-reported anxiety and depressive symptoms were associated with lower levels of resting cardiac parasympathetic activity, and greater state anxiety was associated with higher levels of cardiac sympathetic activity. Findings suggest that midlife women with increased anxiety and depressive symptoms may have an unfavorable cardiac autonomic profile with potential implications for their overall cardiovascular risk.

Prenatal Exposure to PM2.5 and Cardiac Vagal Tone during Infancy: Findings from a Multiethnic Birth Cohort

BACKGROUND

The autonomic nervous system plays a key role in maintaining homeostasis and responding to external stimuli. In adults, exposure to fine particulate matter (PM2.5) has been associated with reduced heart rate variability (HRV), an indicator of cardiac autonomic control.

OBJECTIVES

Our goal was to investigate the associations of exposure to fine particulate matter (PM2.5) with HRV as an indicator of cardiac autonomic control during early development.

METHODS

We studied 237 maternal-infant pairs in a Boston-based birth cohort. We estimated daily residential PM2.5 using satellite data in combination with land-use regression predictors. In infants at 6 months of age, we measured parasympathetic nervous system (PNS) activity using continuous electrocardiogram monitoring during the Repeated Still-Face Paradigm, an experimental protocol designed to elicit autonomic reactivity in response to maternal interaction and disengagement. We used multivariable linear regression to examine average PM2.5 exposure across pregnancy in relation to PNS withdrawal and activation, indexed by changes in respiration-corrected respiratory sinus arrhythmia (RSAc)-an established metric of HRV that reflects cardiac vagal tone. We examined interactions with infant sex using cross-product terms.

RESULTS

In adjusted models we found that a 1-unit increase in PM2.5 (in micrograms per cubic meter) was associated with a 3.53% decrease in baseline RSAc (95% CI: -6.96, 0.02). In models examining RSAc change between episodes, higher PM2.5 was generally associated with reduced PNS withdrawal during stress and reduced PNS activation during recovery; however, these associations were not statistically significant. We did not observe a significant interaction between PM2.5 and sex.

DISCUSSION

Prenatal exposure to PM2.5 may disrupt cardiac vagal tone during infancy. Future research is needed to replicate these preliminary findings. https://doi.org/10.1289/EHP4434.

The transgenerational transmission of maternal adverse childhood experiences (ACEs): Insights from placental aging and infant autonomic nervous system reactivity

OBJECTIVE

To test alterations in placental cellular aging as one pathway by which maternal early adversity influences physiologic development in her offspring.

METHODS

Maternal report of her adverse childhood experiences (ACE) was obtained prenatally along with measures of prenatal stress and demographic information. Placentas (N = 67) were collected at birth and telomere length (TL) was measured in four separate fetally-derived placental tissues: amnion, chorion, villus, and umbilical cord. At four months of age, infants completed the still-face paradigm (SFP) during which respiratory sinus arrhythmia (RSA) data were collected; RSA reactivity and RSA recovery was available from 44 and 41 infants respectively. Multi-level mixed effects models examined the impact of maternal ACE score on placental TL. Generalized linear models tested the relation between composite placental TL and infant RSA, as well as the moderation of maternal ACE score and infant RSA by composite placental TL.

RESULTS

Higher maternal ACE score significantly predicted shorter placental TL across tissues (β = -0.015; P = 0.036) and infant RSA across the SFP. No direct relation was found between placental TL and RSA, however composite placental TL moderated the relation between ACE score and both infant RSA reactivity (β = 0.025; P = 0.005) and RSA recovery (β = -0.028; P = 0.032). In infants with shorter composite placental TL, higher ACE score predicted greater RSA suppression during the still-face epoch relative to play period 1 and greater RSA augmentation during play period 2 relative to the still-face epoch.

CONCLUSIONS

These data are the first, to our knowledge, to report that changes in placental TL influence the transgenerational impact of maternal early life adversity on the development of her offspring's autonomic nervous system.

Autonomic complexity and emotion (dys-)regulation in early childhood across high- and low-risk contexts

Developing the ability to regulate one's emotions in accordance with contextual demands (i.e., emotion regulation) is a central developmental task of early childhood. These processes are supported by the engagement of the autonomic nervous system (ANS), a physiological hub of a vast network tasked with dynamically integrating real-time experiential inputs with internal motivational and goal states. To date, much of what is known about the ANS and emotion regulation has been based on measures of respiratory sinus arrhythmia, a cardiac indicator of parasympathetic activity. In the present study, we draw from dynamical systems models to introduce two nonlinear indices of cardiac complexity (fractality and sample entropy) as potential indicators of these broader ANS dynamics. Using data from a stratified sample of preschoolers living in high- (i.e., emergency homeless shelter) and low-risk contexts (N = 115), we show that, in conjunction with respiratory sinus arrhythmia, these nonlinear indices may help to clarify important differences in the behavioral manifestations of emotion regulation. In particular, our results suggest that cardiac complexity may be especially useful for discerning active, effortful emotion regulation from less effortful regulation and dysregulation.

Can the vagus nerve serve as biomarker for vata dosha activity?

This 'discussion paper' raises 'provocative questions' to identify physiological systems underlying vata dosha and candidate biomarkers for vata activity. We explained the strong correlations between survival and homeostatic functions of the parasympathetic vagus nerve, and functions governed by the five major sub-types of vata dosha (Praana, Udana, Vyaana, Samaana, and Apana). Four reasons were provided to hypothesize that vagal activity is a reliable candidate biomarker of important vata dosha functions. First, normal vata dosha and the vagus maintain neural, respiratory, and digestive homeostasis, and dysfunctions in both entities cause very similar diseases. Second, vata dosha regulates higher neural functions such as mental health and behaviour, and the 'polyvagal theory' proposes similar functions for the vagus. Third, the similar roles of vata dosha and vagus in maintaining gut homeostasis, suggest that vagal activity in the 'gut-brain' link is a candidate biomarker of pakwashaya (lower gut), a primary regulatory site for vata dosha. Fourth, the vagus is the only vital nerve whose activity can be reliably measured and manipulated. Indeed, vagal nerve stimulation is a USA-FDA approved therapy for certain ailments attributed to impaired vata dosha. No other nerve or dosha, has such multi-functional and life-sustaining properties. These arguments position vagal activity as a suitable candidate biomarker for certain functions of vata dosha.

Exposure to antenatal corticosteroids and reduced respiratory sinus arrhythmia in adult survivors of extremely low birth weight

Purpose/aim: Antenatal corticosteroid (ACS) therapy has dramatically increased survival rates among extremely low birth weight (ELBW) infants. However, the long-term effects of ACS on autonomic nervous system function have not been explored. Using the world's oldest longitudinally followed cohort of ELBW infants we compared respiratory sinus arrhythmia (RSA) among ELBW survivors whose mothers received ACS (ELBW-S), those who did not (ELBW-NS) and normal birth weight (NBW) controls in their 20 and 30 s. Methods: Resting electrocardiogram (ECG) was recorded from ELBW-S (n = 28), ELBW-NS (n = 36), and matched NBW controls (n = 79) at 22-26 and 29-36 years. Resting RSA was compared across groups via analyses of covariance (ANCOVA), adjusting for sex, medication use, postnatal steroid exposure and the presence of chronic health conditions. RSA was also compared across assessments for each group. Results: At 29-36 years, resting RSA in ELBW-S was significantly lower than in NBW controls. RSA in the ELBW-NS group was intermediate between ELBW-S and NBW groups. Although the ELBW-S group also showed nominally reduced RSA compared to NBW controls at the 22-26-year visit, this difference was not statistically significant. Conclusions: ELBW survivors exposed to ACS had lower RSA than NBW controls during their 30 s, suggestive of a decline in parasympathetic input to heart. ELBW survivors who received ACS may be particularly vulnerable to cardiovascular problems in later life.

Job Satisfaction Among Mental Health Workers

Abstract. Work characteristics such as job satisfaction have been associated with mental and physical health outcomes in several cross-sectional and longitudinal studies. However, meta-analytic reviews indicate that nearly all of the reported relationships between these two sets of constructs rely on self-report measures. Thus, the magnitude of the reported relationships may be inaccurate and inflated due to common method variance (mono-method bias) and negative affectivity. Respiratory sinus arrhythmia (RSA) is an objective measure of risk for adverse mental health and physical health outcomes. To our knowledge, there has been no investigation of the relationship between job satisfaction and respiratory sinus arrhythmia. In this investigation, 29 workers in mental health settings who experience higher than average levels of work stress due to the amount and unpredictability of workload completed sociodemographic measures and a job satisfaction measure. RSA was then collected during a resting baseline, a worry induction stressor condition where they were instructed to think about work stressors, and a post-stress recovery condition. RSA reactivity to the stressor was significantly greater for participants with low job satisfaction. The low job satisfaction participants also demonstrated less RSA recovery after the stressor ended. Alternatively, participants with higher job satisfaction reacted less and recovered more completely from the stressor.

Presidential Address 2011: Autonomic modes of control and health

Understanding psychosomatic relations, and their implications for heath, is importantly dependent on our conceptual and measurement models. The historical view of reciprocal control of the autonomic branches is applicable in some contexts, but not others. Control of the autonomic branches can vary reciprocally, independently, and even coactively. Assessment of sympathovagal balance, based on a reciprocal model of regulation of the autonomic branches, may have applications in orthostatic contexts and in insulin resistance in diabetes. However, it does not adequately capture the pattern of autonomic control that is relevant for myocardial infarction (MI; in humans) and experimental cardiac arrest (in mice). A measure of sympathovagal balance (cardiac autonomic balance) was predictive and informative of the autonomic contributions to diabetes but was blind to autonomic contributions to cardiac arrest and its sequelae. However, a metric designed to capture the coactivity dimension of cardiac autonomic regulation (CAR) was predictive of MI and its sequelae. Both human and animal model studies revealed that low CAR (low sympathetic and especially low parasympathetic control) predicted the occurrence of MI and the neuroinflammatory consequences of cardiac arrest. These effects were importantly modulated by social support in both humans and animals, via an apparent oxytocinergic pathway that impacts parasympathetic cardiac control and CAR, and thus neuroinflammation. Results indicate the importance of a physiologically meaningful model of autonomic control in understanding health implications of the modes of autonomic control.

Distress tolerance across self-report, behavioral and psychophysiological domains in women with eating disorders, and healthy controls

BACKGROUND AND OBJECTIVES

The tendency to engage in impulsive behaviors when distressed is linked to disordered eating. The current study comprehensively examines emotional responses to a distress tolerance task by utilizing self-report, psychophysiological measures (respiratory sinus arrhythmia [RSA], skin conductance responses [SCRs] and tonic skin conductance levels [SCLs]), and behavioral measures (i.e., termination of task, latency to quit task).

METHODS

26 healthy controls (HCs) and a sample of treatment-seeking women with Bulimia Nervosa (BN), Binge Eating Disorder (BED) and Anorexia Nervosa (AN) (N = 106) completed the Paced Auditory Serial Addition Task- Computerized (PASAT-C). Psychophysiological measurements were collected during baseline, PASAT-C, and recovery, then averaged for each time period. Self-reported emotions were collected at baseline, post-PASAT-C and post-recovery.

RESULTS

Overall, we found an effect of Time, with all participants reporting greater negative emotions, less happiness, lower RSA, more SCRs and higher tonic SCLs after completion of the PASAT-C relative to baseline. There were no differences in PASAT-C performance between groups. There was an effect of Group for negative emotions, with women with BN, BED and AN reporting overall higher levels of negative emotions relative to HCs. Furthermore, we found an effect of Group for greater urges to binge eat and lower RSA values among BED, relative to individuals with BN, AN and HCs.

LIMITATIONS

This study is cross-sectional and lacked an overweight healthy control group.

CONCLUSION

During the PASAT-C, individuals with eating disorders (EDs) compared to HCs report higher levels of negative emotions, despite similar physiological and behavioral manifestations of distress.

Respiratory Sinus Arrhythmia Quantified with Linear and Non-Linear Techniques to Classify Dilated and Ischemic Cardiomyopathy

In congestive heart failure (CHF), dilated cardiomyopathy (DCM) and ischemic cardiomyopathy (ICM) are two highly related pathologies that are not fully characterized. The aim of this study is to assess respiratory sinus arrhythmia (RSA) index of the parasympathetic system, in order to discriminate between both pathologies, DCM and ICM. For this, ECG-signals of 49 subjects (12 DCM patients, 21 ICM patients, 6 ICM patients with diabetes mellitus (DM) type II and 10 control subjects) from the database HERIS II and of 173 subjects (50 DCM, 50 ICM, 15 DCM with DM type II, 15 ICM with DM type II and 47 control subjects) from the database MUSIC2 were analyzed. The RSA was quantified using linear and non-linear analysis methods (fractal dimension and entropy). The results showed a significant difference between ICM and DCM subjects (p=0.013) with a sensitivity of 83% and specificity of 90%. Decreasing RSA values were present in CHF patients, especially in ICM patients, in comparison with healthy subjects. Alterations in the parasympathetic system due to DM were also identified.

Polymorphic variation in the SLC5A7 gene influences infant autonomic reactivity and self-regulation: A neurobiological model for ANS stress responsivity and infant temperament

OBJECTIVE

To examine the impact of polymorphic variation in the solute carrier family 5 member 7 (SLC5A7) gene on autonomic nervous system (ANS) reactivity indexed by respiratory sinus arrhythmia (RSA) and heart rate (HR) in infants during a dyadic stressor, as well as maternal report of infant self-regulation. Given evidence of race differences in older individuals, race was specifically examined.

METHODS

RSA and HR were collected from 111 infants during the still-face paradigm (SFP). Mothers completed the Infant Behavior Questionnaire-Revised short-form. Multi-level mixed effects models examined the impact of SLC5A7 genotype on RSA and HR across the SFP. Linear models tested the influence of genotype on the relation between RSA, HR, and maternal report of infant self-regulation.

RESULTS

SLC5A7 genotype significantly predicted RSA stress responsivity (β = -0.023; p = 0.028) and HR stress responsivity (β = 0.004; p = 0.002). T-allele carriers exhibited RSA suppression and HR acceleration in response to stress while G/G homozygotes did not suppress RSA and exhibited less HR acceleration. All infants exhibited modest RSA augmentation and HR deceleration during recovery. Race-stratified analyses revealed that White T-allele carriers drove the overall results for both RSA (β = -0.044; p = 0.007) and HR (β = 0.006; p = 0.008) with no relation between SLC5A7 genotype and RSA or HR in Black infants. Maternal report of infant orienting/regulation was predicted by the interaction of SLC5A7 genotype and both RSA recovery (β = 0.359; p = 0.001) and HR recovery (β = -1.659; p = 0.020). RSA augmentation and HR deceleration during recovery were associated with higher maternal reports of self-regulation among T-allele carriers, a finding again primarily driven by White infants.

CONCLUSIONS

Early in development, genetic contributions to ANS are evident and predict maternal report of infant self-regulation within White infants, consistent with prior literature. The lack of associations in Black infants suggest that race differences in physiological reactivity and self-regulation are emerging during the first year of life potentially providing early evidence of disparities in health risk trajectories.

Network Architecture Underlying Basal Autonomic Outflow: Evidence from Frontotemporal Dementia

The salience network is a distributed neural system that maintains homeostasis by regulating autonomic nervous system activity and social-emotional function. Here we examined how within-network connectivity relates to individual differences in human (including males and females) baseline parasympathetic and sympathetic nervous activity. We measured resting autonomic nervous system physiology in 24 healthy controls and 23 patients with behavioral variant frontotemporal dementia (bvFTD), a neurodegenerative disease characterized by baseline autonomic deficits. Participants also underwent structural and task-free fMRI. First, we used voxel-based morphometry to determine whether salience network atrophy was associated with lower baseline respiratory sinus arrhythmia (a parasympathetic measure) and skin conductance level (a sympathetic measure) in bvFTD. Next, we examined whether functional connectivity deficits in 21 autonomic-relevant, salience network node-pairs related to baseline autonomic dysfunction. Lower baseline respiratory sinus arrhythmia was associated with smaller volume in left ventral anterior insula (vAI), weaker connectivity between bilateral vAI and bilateral anterior cingulate cortex (ACC), and stronger connectivity between bilateral ACC and bilateral hypothalamus/amygdala. Lower baseline skin conductance level, in contrast, was associated with smaller volume in inferior temporal gyrus, dorsal mid-insula, and hypothalamus; weaker connectivity between bilateral ACC and right hypothalamus/amygdala; and stronger connectivity between bilateral dorsal anterior insula and periaqueductal gray. Our results suggest that baseline parasympathetic and sympathetic tone depends on the integrity of lateralized salience network hubs (left vAI for parasympathetic and right hypothalamus/amygdala for sympathetic) and highly calibrated ipsilateral and contralateral network connections. In bvFTD, deficits in this system may underlie resting parasympathetic and sympathetic disruption.SIGNIFICANCE STATEMENT The salience network maintains homeostasis and regulates autonomic nervous system activity. Whether within-network connectivity patterns underlie individual differences in resting parasympathetic and sympathetic nervous system activity, however, is not well understood. We measured baseline autonomic nervous system activity in healthy controls and patients with behavioral variant frontotemporal dementia, a neurodegenerative disease characterized by resting autonomic deficits, and probed how salience network dysfunction relates to diminished parasympathetic and sympathetic outflow. Our results indicate that baseline parasympathetic and sympathetic tone are the product of complex, opposing intranetwork nodal interactions and depend on the integrity of highly tuned, lateralized salience network hubs (i.e., left ventral anterior insula for parasympathetic activity and right hypothalamus/amygdala for sympathetic activity).

Cardiorespiratory interactions previously identified as mammalian are present in the primitive lungfish

The present study has revealed that the lungfish has both structural and functional features of its system for physiological control of heart rate, previously considered solely mammalian, that together generate variability (HRV). Ultrastructural and electrophysiological investigation revealed that the nerves connecting the brain to the heart are myelinated, conferring rapid conduction velocities, comparable to mammalian fibers that generate instantaneous changes in heart rate at the onset of each air breath. These respiration-related changes in beat-to-beat cardiac intervals were detected by complex analysis of HRV and shown to maximize oxygen uptake per breath, a causal relationship never conclusively demonstrated in mammals. Cardiac vagal preganglionic neurons, responsible for controlling heart rate via the parasympathetic vagus nerve, were shown to have multiple locations, chiefly within the dorsal vagal motor nucleus that may enable interactive control of the circulatory and respiratory systems, similar to that described for tetrapods. The present illustration of an apparently highly evolved control system for HRV in a fish with a proven ancient lineage, based on paleontological, morphological, and recent genetic evidence, questions much of the anthropocentric thinking implied by some mammalian physiologists and encouraged by many psychobiologists. It is possible that some characteristics of mammalian respiratory sinus arrhythmia, for which functional roles have been sought, are evolutionary relics that had their physiological role defined in ancient representatives of the vertebrates with undivided circulatory systems.

Respiratory sinus arrhythmia as a non-invasive index of 'brain-heart' interaction in stress

Respiratory sinus arrhythmia (RSA) is accepted as a peripheral marker of cardiac-linked parasympathetic regulation. According to polyvagal theory, the RSA is also considered as the index of emotion regulation. The neurovisceral integration model posits that parasympathetic modulation of the heart marked by RSA is related to complex nervous regulation associated with emotional and cognitive processing. From this perspective, high resting RSA amplitude associated with a greater withdrawal during stressors and subsequent recovery could represent a flexible and adaptive physiological response system to a challenge. Conversely, low resting RSA accompanied by an inadequate reactivity to stress might reflect maladaptive regulatory mechanisms. The RSA reactivity is different with various types of stressors: while the RSA decreases to cognitive tasks indicating a vagal withdrawal, the RSA magnitude increases to emotional challenge indicating an effective cognitive processing of emotional stimuli. The RSA reactivity to stress could have important implications for several mental disorders, e.g. depressive or anxiety disorder. It seems that the study of the RSA, as a non-invasive index of ‘brain-heart’ communication, could provide important information on the pathway linked to mental and physical health.

Respiratory sinus arrhythmia in the fourth decade of life depends on birth weight and the DRD4 gene: Implications for understanding the development of emotion regulation

INTRODUCTION

The long allele of the DRD4 gene can confer different behavioral and emotional phenotypes depending upon environmental exposure, although the physiological changes underlying these phenotypes are not fully known. We sought to extend this work by assessing the interaction of the DRD4 gene and exposure to perinatal adversity (indexed by extremely low birth weight [ELBW]) on resting respiratory sinus arrhythmia (RSA), a neurophysiological measure of emotion regulation, in adulthood.

METHODS

We examined the interaction between the DRD4 gene and perinatal adversity on RSA at age 30-35 in a longitudinal cohort of ELBW survivors (n = 49) and NBW controls (n = 63). Buccal DNA samples were genotyped for short and long carriers of the exon III DRD4 VNTR gene. Resting RSA was assessed by electrocardiogram.

RESULTS

We report an interaction between birth weight status and DRD4 gene (F = 9.42, p = 0.003) in predicting RSA, such that DRD4 long carriers had the highest and lowest resting RSA depending on whether they were born NBW or ELBW, respectively. DRD4 short carriers were less sensitive to birth weight. Additionally, reduced RSA was correlated with a history of major depressive disorder, suggesting it was a reliable index of emotion dysregulation.

DISCUSSION

These results suggest that the perinatal environment influences autonomic nervous system functioning in individuals with genotypes that confer additional sensitivity. Whether the long-term autonomic outcomes of this environmental sensitivity are beneficial or detrimental appears to depend on the quality of the early life environment, and may influence the development of emotion regulatory and psychiatric problems in adulthood.

Serotonin 2A receptor (5-HT2A) gene promoter variant interacts with chronic perceived stress to modulate resting parasympathetic activity in humans

Decreased resting vagal (parasympathetic) tone is implicated in the development of stress-related disorders, including anxiety and depression. Chronic stress elevates the expression of serotonin 2A receptors (5-HT2A), while activation of 5-HT2A leads to inhibition of parasympathetic synaptic transmission. The T allele of the promoter variant, rs6311 (C>T), of the 5-HT2A gene has been shown to increase the 5-HT2A expression in vitro and to be associated with anxiety and depressive disorders. We thus hypothesized that the 5-HT2A functional polymorphism may influence resting vagal activity among persons with chronically high levels of perceived stress. A total of 1138 well-defined healthy, medication-free Han Chinese were included for 5-HT2A genotyping. The Perceived Stress Scale (PSS) was used to measure the level of perceived stress during the last month and participants were divided into low and high PSS groups. Resting-state heart rate variability (HRV) was used to assess autonomic function. No significant between-genotype difference was found in any HRV variable in the low PSS group (n=610). However, in the high PSS group (n=528), high frequency power and root mean square of successive heartbeat interval differences (both HRV indices of parasympathetic activity) were significantly reduced in T/T genotype carriers compared to C/C homozygotes. Our findings are the first to show that individuals homozygous for the high-expressing 5-HT2A (T) allele exhibit diminished resting vagal tone-an index of stress vulnerability-when experiencing chronically elevated levels of perceived stress. The present results may advance our understanding of the genetic mechanism underlying individual differences in susceptibility to stress.

Higher Heart-Rate Variability Is Associated with Ventromedial Prefrontal Cortex Activity and Increased Resistance to Temptation in Dietary Self-Control Challenges

Higher levels of self-control in decision making have been linked to better psychosocial and physical health. A similar link to health outcomes has been reported for heart-rate variability (HRV), a marker of physiological flexibility. Here, we sought to link these two, largely separate, research domains by testing the hypothesis that greater HRV would be associated with better dietary self-control in humans. Specifically, we examined whether total HRV at sedentary rest (measured as the SD of normal-to-normal intervals) can serve as a biomarker for the neurophysiological adaptability that putatively underlies self-controlled behavior. We found that HRV explained a significant portion of the individual variability in dietary self-control, with individuals having higher HRV being better able to downregulate their cravings in the face of taste temptations. Furthermore, HRV was associated with activity patterns in the ventromedial prefrontal cortex (vmPFC), a key node in the brain's valuation and decision circuitry. Specifically, individuals with higher HRV showed both higher overall vmPFC blood-oxygen-level-dependent activity and attenuated taste representations when presented with a dietary self-control challenge. Last, the behavioral and neural associations with HRV were consistent across both our stress induction and control experimental conditions. The stability of this association across experimental conditions suggests that HRV may serve as both a readily obtainable and robust biomarker for self-control ability across environmental contexts.

SIGNIFICANCE STATEMENT

Self-control is associated with better health, but behavioral and psychometric self-control measures allow only indirect associations with health outcomes and may be distorted by reporting bias. We tested whether resting heart-rate variability (HRV), a physiological indicator of psychological and physical health, can predict individual differences in dietary self-control in humans. We found that higher HRV was associated with better self-control and improved predictions of choice behavior. Specifically, higher HRV was associated with more effective downregulation of taste temptations, and with a diminished neural representation of taste temptations during self-control challenges. Our results suggest that HRV may serve as an easily acquired, noninvasive, and low-cost biomarker for self-control ability.

Psychological and autonomic effects of art making in college-aged students

BACKGROUND AND OBJECTIVES

Anxiety disorders comprise the most common category of mental illness among US young adults. Art making might be one method to help reduce anxiety, but the few studies investigating this have used only subjective measures of anxiety.

DESIGN

This study employed both subjective (self-reported state anxiety from the State-Trait Anxiety Inventory) and objective (heart rate variability) measures to assess whether 30-minute periods of art making reduced anxiety in 47 first-year college students prior to their final examinations.

METHODS

Students participated in free-form painting, mandala coloring, clay modeling, and control sessions.

RESULTS

Repeated-measures ANOVA with post hoc analysis revealed significantly greater pre- to post-session reductions in anxiety for all three types of art-making sessions than for the control session, as measured objectively. Measured subjectively, only free-form painting yielded a significant decrease in anxiety compared to the control session.

CONCLUSIONS

Given the health benefits of anxiety reduction, further study is warranted to determine the duration of art making's anxiety-reducing effect.

Heart rate variability as a transdiagnostic biomarker of psychopathology

The Research Domain Criteria (RDoC), developed by the National Institute of Mental Health as a neuroscience-informed alternative to traditional psychiatric nosology, is an explicitly dimensional system in which classification of psychopathology is derived inductively (i.e., from basic science), across multiple levels of analysis (e.g., genetic, neural, psychophysiological, and behavioral). Although RDoC is often presented as paradigmatically revolutionary, a review of the history of psychophysiology suggests that roots of RDoC thinking extend at least as far back as the mid-20th Century. In this paper, we briefly and selectively review the historical emergence of neurobiologically-informed dimensional trait models of psychopathology, and we summarize our thinking regarding high frequency heart rate variability (HF-HRV) as a transdiagnostic biomarker of self-regulation and cognitive control. When functional interactions between HF-HRV and systems of behavioral approach and avoidance are considered, diverse patterns of behavioral maladjustment can be subsumed into a single model. This model accommodates the general bifactor structure of psychopathology, and suggests that HF-HRV can be viewed as an autonomic, transdiagnostic biomarker of mental illness.

Cardiovagal and somatic sensory nerve functions in healthy subjects

PURPOSE

Heart rate response to deep breathing (HRDB), which depends on the integrity of cardiac vagal preganglionic neurons and efferent fibers, and the function of sural nerve fibers are both associated with an age-related decline process. The aim of this study was to determine whether the effects attributed to aging on cardiovagal and sural nerve function decline are associated.

METHODS

HRDB and sural sensory nerve action potential (SNAP) amplitude, latency, and conduction velocity (SCV) were measured in one hundred healthy asymptomatic subjects (aged 14-92 years, 41 women). Multiple and simple linear regressions were used to analyze the relationships between the variables.

RESULTS

There were significant linear relationships between sural SNAP amplitude and HRDB with age. There was also a significant linear relationship between sural SNAP amplitude and HRDB (correlation coefficient 0.46, p<0.0001), but the model explained only 21.5 % of the variability in HRDB.

CONCLUSION

Cardiovagal function assessed by HRDB is associated with sural SNAP amplitude in healthy subjects. Age-related decline only partially explained the variability seen in the association. Other genetic and environmental factors may also play a role.